Degasifier



Sept. l2, 1950 R. A. wHrrLocK, JR., ErAL 2,522,005

DEGASIFIER Filed Nov. 15, 1946 Patented Sept. 12, 1950 DE'GASIFIERRobert A. Whitlock,` Jr., and'tJames E. Dymond,

Rockford, I1l., assgnors tof AutomaticPump & Softener Corporation,RockfordJll., ay corporau tion of Illinois Application November 15,1946, Serial N o.` 709,940

(Cl. 18S-2.5)

10` Claims. l

.This invention. relates tot improvements in the degasification ofliquids,` particularly to: an im.- proved method and apparatus forremoving dissolved gas instepwise fashion.

An object of the invention is the `provision of amethod andv means forremoving .absorbed gas from. a liquid withoutthe use of Aany powersource other than the pressure energy in the liquid itself.`

In general, the invention contemplates diifus, ing the liquid into a lowpressurearea where an initial,l partial degasification is caused to takeplace, venting off the removed gas. and then passing the liquid througha, vessel which exposes a large surface area of the liquidto furtherdegasify it, and then venting the gas from the vessel.

Other objects and advantages will become apparent from the followingdescription in connecn tion -with the drawings, in which- Figure 1 is aView of one. form of the present. invention; H

Fig. 2 is a sectional View .of Figure l taken along line 21-2 showingthe perforated nozzle inthev aspirator;

Fig. 3 is a sectional View of Figure 1 taken'along I Referring now moreparticularly to the draw# ings, which show an embodiment kadaptedparticularly for the removal of carbon dioxide from water emerging fromanion exchanger, a vessel I,*containing a bed 2 of coke or othermaterial for'the liquid to percolate over, is provid-edwith a liquidinlet 3 and outlet 4 and withan air inlet- 6 and outlet 'I. The airinlet is provided with a tubular screen 8 which in this instance servesto distribute atmospheric air across the bottom of thev bed 2.

The liquid under treatment enters the system under` normal. watersystempressure through av pipe l Iv1 in the example given thispi-pebeing connected to an anion exchanger (not shown) and is directedthrough an injector comprising a nozzle I 2 and a `diifuser tube i3. Forbest results the liquid should pass through the nozzle at twentyve.pounds or more per square inch. .In this particular instance the nozzlei2 is provided with a number of relatively small perforations I4 out ofWhich the liquid discharges under relatively pressure, the individualstreams beingglso arranged as to break up or atomize-in close proxyVimity to the nozzle into a spray. This is facili-l tated by theprovisicnof means for breaking up.

the stream emerging from the nozzle, one meansbeing., as herein shown, aplurality of pieces of gravel indicated at IIJ which `causes the waterpassing through the perforation-s I4 to assume a swirling motion as itemerges from the nozzle. While we prefer to perforate the nozzle inthisv manner, other specific nozzle constructions will.

operate satisfactorily; in general we have found that a nozzle thatdirects the liquid into diffuser tube I3- of the injector in a high.velocity turbum lentmanner is best for: effecting this primaryclegasiiication. This high velocity diffusion ofv fluid into the tube t3creates a low pressure in a suction conduit. lo through. which air is'drawn through inlet 6 together with gas released from the liquid in thevessel in the secondary degasication; this latter gas composition isentrained in the fluid entering the diffuser tube I3 and is carried to aseparation point, in this instance az, T II which functions as aprimary'separation chamber from which the mixture of gases is vented tothe atmosphere or to a suitable receiver through. vent pipe I 8. Thepartially degasied liquid is directed downward through conduit ISl intothe vessel I. A liquid seal, having a level shown at 2|, is provided toprevent the recycling vof gas from the diffuser tube I3 through thevessel I. The level 2l: -is controlled by adjustment of a valve 22 sothe level is below the separator v T Ilv to permit the separated gasesto flow freely out of vent pipe I 8*, and the diffuser tube I3 isvinclined downward slightly in the direction of.

The best results the T to facilitate drainage. appear to be obtained ifthe tube I3 is disposed ina vertical position with the nozzle above, butthis so increases the height of the device as tov render itimpractcal'in most instances. VThis iiuid seal may be maintained' in anyother suite able manner to give satisfactory results, as for pieces ofcoke, etc., the liquidis thereby spread Y `out in a thin film underreduced pressure in con" tact with the upwardly moving gas, which inthis case is atmospheric air drawn through the yin-l let 6 by action ofthe injector. Flow throughthe vessel isv thus. countercurrent.

The liquid pipe I3 was 11/2" in diameter and 18 long, the' Waterpressure in pipe Il was sixty pounds per square inch, the perforationsi4 were No. kiid f drill holes disposed at diverging angles ofapproximately 5 degrees with the longitudinal centerline of the nozzeland the iiow rate of water through the bed was 4.3 gallons per minutefoot of 4cross-sectional area. The effectiveness of the degasificationis illustrated by the following figures which have been determined fromactual tests: With the inlet water in conduit Il containing' 200 partsper million of absorbed carbon dioxide gas, the water in the liquid seal2i showed a gas content of 75 P. P. M., after the initial degasiflcationby the aspirator 9; and the water leaving the vessel I' through conduit2 shows a final gas content of approximately 5 P. l?. M. Attention isdirected to the fact that the action of the diffuser is to reduce thepressure in the tank l to below atmospheric, and that the reduction inpressure may be controlled by adjusting the usual well known factors. Inpractice we have produced a vacuum as low as 6 inches of water in thetank I. This reduction in pressure materially assists in the removal ofgas from the liquid and greatly reduces the amount of dissolved air inthe eiiluent water emerging from the tank l.

It will thus be obvious that the device pro- 'videsa highly eiiicientmethod and apparatus for degasifying liquids which utilize no outsidesource of power other than the initial pressure energy in the liquiditself. Furthermore, both degasification steps are carried out atsubstantially atmospheric pressure or less, so that relativelyinexpensive low pressure equipment may be employed.

While the speciiic test results given above are those determined whenrunning the degasifier as a decarbonater, it will be understood that theinvention is applicable generally to the eiective removal of gases fromliquids. Furthermore, while the inlet 6 is illustrated as usingatmospheric purging air to sweep the secondarily released gas out of thevessel l, it will be obvious that other sweeping gases may bel employedto better advantage in certain instances, as for example, where theliquid to be degasied is a potentially explosive hydrocarbon or the likewhich must be kept out of Contact with air. 'llhe invention alsocontemplates thatin certain cases where the object is the removal of thegreatest possible amounts of all gases from the liquid, the sweeping gasinlet 6 may kie/omitted altogetherl and the vessel l maintained under asuitable vacuum by the aspirator .9. While the vesselv l has been shownpacked with a bed of coke or like particles for the liquid to trickledown over, other` modifications-of this varrangement may besatisfactorily employed. For example, a series of.

screens, wood slats, balls, etc. may be used to expose the greatestpossible liquid surface area for release of the absorbed gas.

.While al particulanformvoi the present invention has been shown, itwill be apparent that minor changes therein will readily suggestthemselves to others skilled in the art without departing from thespirit and scope of the invention. Having thus described the invention,what is claimed as new is:

v (1. In a methodof removing av dissolved gas from a liquid: a rst stepof atomizing said liquid in the form of a line spray into anenvironiment of a non-condensible gas of composition dilerent from thatof the dissolved gas to at least partially remove said. dissolved gas;and a subsequentstep of trickling the partly degasiiied liquid over abed of material in an environment of said gas of diierent composition toeffect substantial further degasication of said liquid.

2. In a a method of removing a dissolved gas from a liquid; a step ofspraying a stream of said liquid to atomiae the liquid and entrain anon-condensible gas of different composition from said dissolved gasinto said stream to at least partially eiect the removal of said one gasfrom said liquid; a subsequent step of venting the mixture of gases fromsaid stream and thereafter directing said liquid through a containercountercurrent to the flow of said gas of different composition to eieeta further substantial removal of said dissolved gas from thev liquid.

3. In a method of degasifying a liquid, the

steps of: passing a stream of said liquid through an aspirator to causethe aspirator to draw gas of diierent composition through a bed ofsolidI material and into the stream; venting the gases in said streamfrom the liquid; and thereafteri directing said liquid through said .bedn contact with said gas of different composition.

4. In a method of removing a gas from a liquid, the steps of: dispersinga, stream of the liquid to entrain a stream of air and to draw thelatter through a chamber under sub-atmospheric pressure, the dispersionof said liquid stream and the entrainment of said air stream beingeiective to remove at least a portion of said gas from the liquid;venting oli the removed gas and entrained air; and passing the partlydegasied liquid through said chamber in contact with the air stream atsub-atmospheric pressure to further eiect the removal of said gas.

5. In apparatus for removing a gas from a liqy uid, a vessel having aliquid inlet and outlet and s, having a gas outlet, aspirator meansconnected to a source of said liquid under pressure for dispersing saidliquid to eect a partial degasifly cation thereof, said aspirator meanshaving a suction inlet connected to said vessel gas outlet to withdrawgas therefrom to reduce the pressure increasing the surface area of saidliquid as it` passes therethrough to enect a further degasiflcationthereof, said gas being withdrawn through said gas outlet by saidaspirator means.

6. In apparatus for removing a gas from av liquid, a vessel having aliquid inlet and outlet and having a gas inlet and outlet, an aspiratorconnected to a source of said liquid under pressure for directing saidliquid into an initial separator to eiect an initial partialdegasication thereof, said aspirator having a suction inletcon-v nectedto said vessel gas outlet to withdraw gas therefrom and entrain it inthe dispersed liquid flowing to the initial separator, said separatorhaving a vent for separating gas from the partially degasied liquid, aconduit connecting the separator with the vessel, said vessel havingmeans therein for spreading said liquid out over an increased surfacearea in the presence of gas entering said gas inlet to effect a inaldegasication of the liquid, the gas removed from the liquid in thevessel being swept out-0f the gas outlet by the gas entering said gasinlet.

7. An apparatus for removing carbon dioxide and other gas from watercomprising a vessel having a liquid inlet adjacent the Atop thereof anda liquid outlet in the lower portion thereof and also having an airinlet in the lower portion of the vessel and a gas outlet in the upperportion thereof, an aspirator connected to a source of water containingsaid gas under pres' sure for directing the water into an initial separator to eiect partial decarbonation thereof, said aspirator having asuction inlet connected to the gas outlet of said vessel to draw gasupwardly through the vessel from the air inlet and entrain it in thedispersed water ilowing from the aspirator, said separator having a ventfor the escape of air and gas therefrom, means for connecting theseparator with the water inlet of the vessel, said means including atrap for preventing return flow of air to the vessel, and means disposedin the vessel for spreading the water over a wide surface area incounterilow relation with the air entering the air inlet to effect iinalremoval of the gas from the liquid by the air entering the gas inlet.

8. In apparatus for removing a gas from a liquid, a vessel having aliquid inlet and outlet and having a gas inlet and outlet, an aspiratorhaving a plurality of small openings providing communication between asource of said liquid under pressure and a diiTuser tube for sprayingsaid liquid in a plurality of streams into said diuser tube, saidaspirator having a suction inlet connected to said vessel gas outlet todraw gas therefrom to reduce the pressure in said vessel and entrain thegas in the spray entering the diluser tube, the spraying of said liquidbeing effective to partially degasify said liquid,

said diiuser tube discharging into an initial separator effective tocollect the partially degasined liquid and vent the gases therefrom',said initial separator having connection with said vessel to conveythepartially degasied liquid thereto, said vessel having a bed ofmaterial therein for said liquid to flow over to expose a large surfacearea of the liquid to gas drawn into the gas inlet and through the bedby the action of said aspirator.

9. In apparatus for degasifying a liquid, a vessel having a liquid inletand outlet and a gas outlet, jet means connected to a source of saidliquid under pressure for atomizing said liquid into a relatively lower`pressure zone to effect partial removal of the gas therefrom byeffervescence, means connecting said low pressure zone to the gas outletof said vessel to evacuate gas therefrom, a separator for separating theremoved gas from the partially degasied liquid, means for venting thegas from said separator, conduit means for thereafter conveying thepar'- tially degasied liquid into said vessel to further degasify it,and a liquid seal in said conduit means to prevent the cycling of gasfrom said liquid inlet to said gas outlet.

10. Apparatus for removing an undesired gas from liquid containing thesame comprising a vessel having a liquid inlet and outlet, meansconnected to a source. of said liquid under pressure for atomizing saidliquid and suddenly releasing pressure therefrom into an atmosphere of agas of different composition to cause circulation of the latter gasthrough the apparatus and effect at least partial removal of saidundesired gas from the liquid by effervescence, means for venting saidgas of different composition and admixed undesired gas from theapparatus, and means for thereafter directing the partially degasiedliquid through the vessel in a direction counterflow to the aforesaidgas of different composition to effect further removal of the undesireclgas.

ROBERT A. WHITLOCK, JR. JAMES El. DYMOND.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 457,917 Shaw Aug. 18, 18911,612,218 Piron Dec. 28, 1926 1,725,925 Kent Aug. 27, 1929v 1,800,217Jacobus Apr. 14, 1931 1,836,338 Rodman Dec. 15, 1931 1,916,922 Dow July4, 1933 1,955,321 Burch Apr. 17, 1934 2,047,157 Rodman July 7, 19362,136,774 Hickman Nov. 15, 1938

